Coated fabric and process of making same



Patented June 1, 1937 UNITED STATES PATENT OFFICE COATED FABRIC AND PROCESS OF MAKING SAME No Drawing. Application March 9, 1934, Serial No. 714,840

8 Claims.

This invention relates to treated fabrics which are water repellent and waterproof, and more particularly to flexible coated fabrics which may serve as coverings for mattresses and the like or useful wherever the properties of water. repellency and Waterproofness are desirable and necessary.

Coated fabrics have been used in the past as mattress coverings for cribs and as protective covers for mattresses in hospitals to prevent wetting and staining by water, blood, urine, body 1 exudates, liquid medicaments, etc. In such instances the coated side of the fabric had been placed uppermost on the mattress so as to present a liquidproof surface. Fabrics for this purpose have been coated on one or both sides with usually cellulose derivative coating compositions or with rubber compositions. These materials while satisfactory in some instances, possess certain objections from the standpoint of appearance and service quality. Such fabrics are'known in the art as fully coated, that is they have a continuous film deposited from a coating composition on one or both sides of the fabric. The appearance of the weave of the fabric which is desirable for a number of reasons is thus hidden and the surface presents a smooth appearance. The coatings commonly used either of a cellulose derivative or rubber composition are durable from the standpoint of resistance to abrasion but in time tend to crack due to the repeated foldings of pleats formed by the movement of the body on the mattress. These cracks, when they develop, destroy the liquidproofness of the covering even when the material has a coating on both sides, moreover, the double coated material is heavy and bulky and difficult to handle when applied to mattresses or objects to be protected. Further, these fully coated materials are not entirely satisfactory from the standpoint of comfort to the body since the protective coating is essentially impervious to moisture and heat thus causing discomfort from the accumulation of perspiration, etc.

This invention has as an object the provision of a treated fabric product which will overcome 45 the objections to the known type of material as described above. A further object is the provi- Sion of treated textiles which are decorative in appearance and of general utility in the art or manufacture of waterproof articles. A still further object is to impart to fabrics waterproof and water repellent properties which they do not naturally possess without destroying the fabric weave on the face of .the material.

ing invention in which a suitable textile fabric is subjected to a treatment to make it water repellent and then to one face or side is applied a suitable coating of a cellulose derivative composition to form a continuous film which is waterproof.

The invention in its preferred embodiment is carried out according to the following procedure:

A woven-fibrous textile having a weave and weight suitable for the intended purpose of the finished product and on which a design or colored decoration may have been'produced by weaving, dyeing, printing or other suitable means known to the art, is impregnated or saturated with a composition of the following approximate formula by weight:

Percent Cellulose derivative 3.0- 3.0 Softener 6.0- 4.0 Wax 4.0- 3.0 Mineral oil 3.0- 9.0 Solvent mixture 84.0-81.0

A preferred detailed composition contains:

' Percent After impregnation or saturation the material is suitably dried by passing through a heated chamber to expel the solvents. The material thus made water repellent is then coated on one side of the fabric which has been selected as the wrong or reverse side, with a coating of the following approximate composition:

, Percent Cellulose nitrate 32.0-39.0 Softener 44.0-46.0 Pigment 24.0-l5.0

To deposit this composition the ingredients are dispersed in organic dispersing media similar to those used for the water repellent composition and well known to those versed in the art of using such compositions. This coating composition is applied by any suitable means as for example, by a doctor knife, roller coating or spray coating and subjected to drying to remove the volatile ingredients. One or more coats of this composition may be applied with suitable drying between each application. The quantityof coat- 2 aosauea ing applied-will vary with and depend upon the type of weave of the fabric being treated as well as the weight of the fabric. Sufficient of the composition should be applied to form a continu- 5 ous film on-the fabric and one which will meet the requirements for waterproofness as discussed hereinafter. After the. application of the coating composition the composite material is subjected to a, smoothing operation preferably by passing between hot rolls usually heated to about 150 to 200 C. This treatment does not affect the appearance of the weave of the fabric but smooths the coated side of the material. If desired, rolls having engraved thereon closely lying parallel lines may be used for the smoothing operation. Such a treatment will produce a satiny effect on the finished product. After the smoothing treatment the material is ready to be made into mattress covers or other protective coverings. When used for mattress covers, if they are made with the uncoated side out, they have the appearance and "feel" of the ordinary untreated cloth.

In the present invention the terms water repellent and waterproof are used to describe two degrees of resistance to water possessed by a fabric. By water. repellent, is understood the ability of the fabric to withstand a shower of water on its surface without any penetration of water through the fabric to the reverse side. A

suitable procedure for determining water repellency is that described by Matthews in The Textile Fibers, 4th edition -(.l924.) Wlleypage 991. This test is described. as a modified spray method and is as follows: i

Dry the pieces of fabricused in conducting the funnel test at45 deg. C. for 24 hours, hang in laboratory overnight and. lamp loosely in a frame. Set the frame in a older attached to a trough at an angle of 45 degrees.

Allow clear tap water at room temperature to fall from a height of 6 feet upon the central portion of'the fabric, covering an area of about 8 inches in circumference, for 24 hours, from a 2%" brass spray nozzle having 25 holes, each 1.9 (0.75 in.) mm. in diameter, at a rate of 1000 cc. per minute.

Inspect the condition of the under-side of the fabric at the end of five minutes, one-half hour, one hour, three hours, seven hours, and twentyfour hours. .Note at each inspection whether the under surface is dry, damp or wet with no dripping; damp or wet with dripping."

B'y waterproofness is understood the resistance of the fabric to adefinite. hydrostatic pressure without any passage of the water through the fabric. A satisfactory test for determining the waterproof quality of a fabric has been found to be to fasten a suitable portion of the fabric over the opening of a water pipe so that the water may be forced up against the under face of the fabric. The hydrostatic pressure necessary to just force water through the fabric is taken as the index of the waterproof quality. In carrying out this test the hydrostatic pres- 6 sure should be applied at a predetermined constant rate.

, While cellulose nitrate is given as the cellulose derivative in the compositions for water repellent treatment of the fabric, other cellulose derivatives as cellulose acetate, cellulose propionate, or cellulose aceto-nitrate may be used as well as cellulose ethers such as ethyl and benzyl cellulose. The softener used in the composition may be any one of the derivativa com- ?5 monly used in the art of softening cellulose derivative films, such as for example, raw castor oil, blown castor oil, blown cottonseed oil, dibutyl phthalate, tricresyl phosphate, or benzylbutyl-phthalate may be used. The wax which may be used may be either of natural or synthetic origin preferably with a melting point lying between the range of 42 to 86- degrees C. Any essentially water-white non-volatile heavy petroleum oil has been found to be satisfactory as the mineral oil constituent. The solvent or dispersing media may be a mixture of various solvents for the cellulose derivative and a solvent for the wax and petroleum oil. Combinations of esters and/or ketones with alcohol and hydrocarbons are particularly useful.

In the composition used for depositing a continuous film, the softener used may be any one of the commonly used plasticizers for cellulose derivatives such as dibutyl phthalate, tricresyl phosphate, amyl phthalate, or stearate of the 'monoethyl ether of ethylene glycol, etc. The

pigment used in this composition is selected preferably so that the color will match the. dominating color in the dyed or decorated fabric, although it is understood that any color may be used, or that a non-pigmented film may be deposited if this is desirable.

Various types of fabrics may be treated by the process of the invention, for example, plain weaves as sheeting, ducks, canvas, ortwill weaves as drills, sateens, broken twills and moleskins of various weights may all be used equally well. The choice of fabric will depend, of course, or be dictated-largely by the particular purpose for which the ultimate product is to beused,

and the choice will be readily apparent to those skilled in the art of using such materials. The invention is not limited to the use of fabrics of a particular type of fiber, natural or synthetic fibers being satisfactory, such as rayon of various types, natural silks, satins, etc.

The product of the invention is admirably adapted for use wherever a flexible, water repellent and waterproof fabric whose outer surface displays an unmarred weave appearance is desirable or necessary; As examples, but not by way of limitation, may be mentioned water repellent and waterproof mattress covers, protective aprons and general wearing apparel for use in tonsorial shops and beauty parlors, bibs, hospital sheetings, garments as wind breakers, tarpaulins, etc., Other uses will readily suggest themselves from the desirable properties and characteristics possessed by the product of the invention.

The productof the invention combines the properties of waterproofness and water repellency, while at the same time retainingthe appearance of the woven textile. When used as mattress covering, for example, it presents the advantage over materials of the prion art of not being subject to cracking and peeling due to disintegration of the film, since the surface presented to the liquids is the uncoated water repellent side or face. Further, the material adds to the comfort of the human body because of the softness of the uncoated fabric by allowing free access of air due to the interstices in the weave of the fabric, a circumstance not possible with the continuous film of mattress coverings of the prior art.

Treatment of the fabric while imparting water repellent and waterproof properties, does not appreciably affect the pliability or flexibility, and does not appreciably add to the weight making it cumbersome to use as is the present type material. Also the natural" appearance. of the fabric is retained and it maybe washed in water with neutral soaps very much the same. as an untreated fabric. It is apparent that many widely diflerent embodiments of this invention may be made without departing from the spirit and scope thereof and, therefore, it is not intended to be limited except as indicated in the appended claims.

I claim 1. Process for producing a flexible, waterproof material comprising impregnating a suitable textile fabric with a composition having the approximate formula by weight:

a Per cent Cellulose derivative 3.05 Dibutyl phthalate 6.00 Ceresin wax 4.05 Paraffin il 3.00

Ethyl acetate 22. so Ethyl alcohol 32. 60 Toluene 28. 70

applying to one face of said impregnated fabric a continuous mm of a composition of the approx- 25 imate formula by weight:

Percent Cellulose nitrate 32.0 Softenera Y 44.0

v Pigment 24.0

dispersed in an organic dispersing agent, the amount of the impregnating composition applied to the fabric beinginsufiicient to destroy 35 ghleiaffbric weave on the face of the finished ma- 2. Process for producing a flexible, water repellent and waterproof material comprising treating a suitable textilefabric with a cellulose derivative water repellent'composition having the ap- 40 proximate formula by weight:

Per cent.

Cellulose derivative 3.05 Dibutyl phthalate 8.00 Ceresln w x 4.05 45 Paramn oil 3.00 Ethyl acetate 22. 60 Ethyl alcohol 32.60 Toluene 28. '70

50 applying to one face of said treated fabric a continuous film of a cellulose derivative composition of the approximate formula by weight:

. Per cent Cellulose nitrate 32.0 55 Softener 44.0 Pigment 24. 0

suitably dispersed in an organic dispersing media 60 and smoothing said continuous film by passing side of the said fabric with a cellulose derivativecomposition in amount suiilcient to yield a thin 75 continuous film whereby the said fabric is rendered water repell and W erproof. the amount of the impregnating composition applied to the fabric being insufficient to destroy the fabric weave on the face of the finished material.

4. A flexible waterproof material comprising a water repellent fabric base having a thin continuous coating of a cellulose derivative on one side thereof, the said fabric base being impregnated with a wax and a wax retaining cellulose derivative in an amount sufficient to obtain water repellency but insuillcient to obliterate the weave of the fabric, the water repellent composition being in the form obtainable by impregnating the fabric with a solution of the wax and cellulose derivative and expulsion of the solvent medium, the said solution comprising about 3% cellulose derivative, a plasticizer therefor, a wax and suillcient solvent medium to makes. thin solution, the continuous coating being attached to the fabric base in the manner obtainable by spreading a composition comprising the cellulose derivative and a softener therefor onthe dry impregnated water repellent fabric and drying the resultant.

5. The process for producing a flexible waterproof material which comp -es uniformly impregnating a suitable textile abric with a composition having the approximate formula-by weight:

. Per cent Cellulose derivative 3.0- 3. 0 Softener 6. 0- 4. 0 Wax 4.0- 3. 0 Mineral oil 3. 0- 9.0 Solvent mixture 84.0-81.0

removing the solvent medium and applying to one face of the impregnated fabric a continuous coating a composition having the approximate formula by weight:

Per cent Cellulose nitrate 32. 049.0 Softener 44.0-46.0 Pigment 24. 0-15. 0

dispersed in an organic dispersing medium, the amount of the impregnating composition applied to the fabric being insuflicient to destroy the fabric weave on the face of the finished material.

6. The process for producing a flexible waterproof material which comprises uniformly impregnating a suitable textile fabric with a com-' position having the apprbximate formula by weight:

Percent Cellulose derivative 3.0-3.0 Softener 6.0-4.0 Wax 4.0-3.0 Mineral oil 3.0-9.0 Solvent mixture 84.0-81.0

removing the solvent medium and applying to one face of the impregnated fabric a continuous coating a composition having the approximate formula by weight:

Percent Cellulose nitrate 32.0-39.0 Softener 44.0-46.0 Pigment 24.0-15.0

'I. A flexible water proof material comprising a water repellent fabric base having a thin continuous coating of a cellulose derivative on one side thereof, the said fabric base being impregnated with a wax and a wax retaining cellulose derivative in an amount sufficient to obtain water repellency but insumcient to obliterate the weave of the fabric, the water repellent composition being in the form obtainable by impregnating the fabric with a solution of the wax and cellulose derivative and expulsion of the solvent medium, the said solution comprising:

Percent Cellulose derivative 3.0-3.0

Softener 6.0-4.0 Wax 4.0-3.0 Mineral oil 3.0-9.0 Solvent mixture 84.0-81.0

the continuous coating being attached to the fabric base in the manner obtainable by spreading a composition comprising:

Percent Cellulose nitrate 32.0-39.0 Softener 44.0-46.0 Pigment 24.0-15.0

dispersed in an organic dispersing medium on the dry impregnated water repellent fabric an drying the resultant.

8. A flexible water proof material comprising a water repellent fabric base having a thin continuous coating of a cellulose derivative on one side thereof, the said fabric base being impregnated with a wax and a wax retaining cellulose derivative in an amount sufficient to obtain water repellency but insufllcient to obliterate the weave of the fabric, the water repellent composition being in the form obtainable by impregnating the fabric with a solution of the wax and cellulose derivative and expulsion of the solvent the continuous coating being attached to the 'fabric base in the manner obtainable by spreading a composition comprising:

Percent Cellulose nitrate 32.0-39.0 Softener 44.0-46.0 Pigment 24.0-15.0

dispersed in an organic dispersing medium on the dry impregnated water repellent fabric and drying the resultant.

EDGAR H. 'NOLLAU. 

